Change BlockWithSide to place question mark on blocks that are predicates.
Changed block name generation so "getID" would become "get_id", not "get_i_d".
Improves BlockWithSide static factory method by having it set good default
values for helpUrlType and stmtConns if they have not been set by caller.
Fixes BlockWithSide code generation to handle either expressions or statements.
Previously, only expressions worked (which had been all that was needed for
Peripheral).
Added Disk API except for disk.setLabel().